When two user equipment terminals (e.g., mobile communication devices) of a cellular network or other telecommunication system communicate with each other, their data path typically goes through the operator network. The data path through the network may include base stations and/or gateways. If the devices are in close proximity with each other, their data path may be routed locally through a local base station. In general, communications between a network node such as a base station and a wireless terminal is known as “wide area network” (“WAN”) or “Cellular communication”.
It is also possible for two user equipment terminals in close proximity to each other to establish a direct link without the need to go through a base station. Telecommunications systems may use or enable sidelink direct communication, in which two or more user equipment terminals directly communicate with one another. Sidelink direct communication is also sometimes referred to as device-to-device (D2D) communication. In sidelink direct communication, voice and/or data traffic (referred to herein as “communication signals”) from one user equipment terminal to one or more other user equipment terminals may not be communicated through a base station or other network control device of a telecommunication system.
Various aspects of sidelink direct communications are described in one or more of the following, all of which are incorporated herein by reference in their entirety:
U.S. patent application Ser. No. 14/660,528, filed Mar. 17, 2015;
U.S. patent application Ser. No. 14/660,491, filed Mar. 17, 2015;
U.S. patent application Ser. No. 14/660,559, filed Mar. 17, 2015;
U.S. patent application Ser. No. 14/660,587, filed Mar. 17, 2015;
U.S. patent application Ser. No. 14/660,622, filed Mar. 17, 2015;
U.S. patent application Ser. No. 14/749,898, filed Jun. 25, 2015;
U.S. Provisional Patent application 62/055,114, filed Sep. 25, 2014;
U.S. Provisional Patent application 62/104,365, filed Jan. 16, 2015;
What is needed are methods, apparatus, and/or techniques which for allocating resources for sidelink direct communication in a manner that facilitates either resource collision avoidance or resource pre-emption.